perhaps we need a hypothetical extreme example to explain:
assuming the pole were ice-free in march, until when do you think could even larger re-freeze occur, i say may, even june would be possible. on the other hand if the ice edge were very far south in march what chance do you see that significant re-freeze could occour in june, may or even april, close to zero chance IMO.
so now please don't argue that it cannot be ice-free in march and seas around iceland cannot be frozen in march as well. it's just the extremes to illustrate the logics and then there "is" evidence just watch all the recent years with relatively late re-freezes before a steep drop. and we were not explicitely talking abou the max but about the latest ups in ice extent, re-freezes on significant scale very late in the season, it does not matter in this context whether the re-freeze will lead to new highs like in 2012 or not like last year. of course thickness has an impact as well, hence we could agree to replace the term extent to a certain degree with volume, but only if that volume is not boosted by extreme volumes in few places like the canadian archipelago. IMO it's absolutely logical and if you can't see this now we gonna talk again in 5-10 years when this and last years pattern became more regular and probably closer to the extreme i mentioned above ( only closer, of coure there will be always ice in winter for the coming milleniums for sure)
EDIT: since the pattern is relatively new and things are ever changing very rapidly of course no-one is able to come up with evidence gathered over decades like extent and area development, which is why i refer to the logic and used those extrem examples, quasi as an eye opener.